Hot water heat control



April 1941- E. E. GOEHLER 2,238,352

HOT WATER CONTROLI' Filed. Dec. 18, 1930 INVENTOR ATTORNEY Patented Apr. 15, I941 UNITED STATES PATENT OFFICE nor WATER HEAT CONTROL Elmer E. Goehler, Portland, Oreg. Application December 18, 1939, Serial No. 309,706 4 Claims. 01. 237-63) residences, stores and other buildings Where the circulation is of necessity constant, but the addition of heat to the circulating air is a matter for critical regulation. 7

It is also very useful in warm air circulating systems employing intermittent circulation of the warmed air, if the warming of the circulated air is done by hot water, which by'my system is very effective and the control of the invention, hereinafter described, requires only minor changes to adapt to either type as will hereinafter appear. I

Systems of the kind first mentioned will have power air circulation means consisting of a motorized fan or the like, filters and humidifying means, a heating means for use when demand requires it and a system of ducts; all, of which are well known in the art.

Where hot water is employedas the heating means, there will be a hot water boiler, a heat exchanger located in the path of the air drawn to or expelled by the fan and in some manner the heat delivered will be controlled by a thermostatic control that is sensitive to temperature in the space to be heated.

Where the circulation is constant, the application of heat to the circulated air Will be regulated and where the circulation is intermittent, heat will be applied to the air in predetermined amounts and temperature will be regulated as before by thermostatic control located in the space to be heated, which in this other case interrupts the circulation of warm air when temperature reaches the optimum.

Constant circulation with the control on the heat is more expensive though advisable where a considerable number of people use the air conditioned space.

It is the object of the present invention to provide a better and more uniform as well as a more economical addition of heat to circulated air, in either case, than is believed to be at present available.

' In either type of circulating system it is important to provide a practically instantaneous cut-01f device for the heat, going from the boiler e tothe exchanger, since it will necessarily be hot when the thermostat works the remote control and heat stored in the hot water contained in the exchanger itself will tend to extend the heat delivery, Without the acting of some in- It is therefore an important object of the invention to so construct the heat exchange part of the system that these instruments are dispensed with. If thermosyphon circulation is not stopped, with intermittent air, the furnace room becomes very hot with important fuel waste and a blast of very hot air will occur when the fan starts.

The foregoing and other objects that will be apparent to those skilled in the art 'to which this invention appertains are accomplished by the structures diagrammatically illustrated in the drawing, which accompany and form a part of this specification, illustrating both forms of applying the principles of the invention.

The illustrations are to be understood as illustrative only and not as defining limits. scope of the invention is to be ascertained from the claims which conclude this specification.

In the drawing Fig. I is an elevation showing a hot water boiler and other cooperative structures as hereinafter more fully described; the view being partly in section;

Fig. II is a plan view of the structure shown in Fig. I, in orthographic projection; and

Fig. III is a partial view of a modified form of the right hand part of the before mentioned causeit will be the same when this modification is employed.

In the drawing, I is a hot water boiler of any approved type, 2 is a burner which may use oil or gas fuel and 3 conventionally represents a temperature (or pressure) sensitive control for the burner 2.

The control 3 is of the demand type which when the burner is started will heat the boiler, raise the temperature of the boiler to a predetermined point and then cut off or slow down the action of the burner 2. The operation of the boiler will thus be entirely independent of other controls connected to the system, being responsive to heat demand only.

4 is a heat exchanger, preferably of the cellular type that are so efiiciently used in automotive vehicle radiators,'and it will be noted that it is set horizontally. This is purposefully done to defeat any tendency to thermosyphon circulation. The exchanger 4 preferably omits the customary and reservoir portions commonly used in radiators for automotive vehicles, because it is desirable that the volume of heated water in it at any given time be kept as low as its radiation capacity will permit.

The exchanger 4 is set horizontally well below the top of the boiler I, as shown in Fig. I and this'is important. Of still greater importance is the fact that both circulation pipes 5 and 6 are connected to the top of the boiler, at the done merely for clarity as it is preferably connected up with the inlet and return pipes at the same level, though if the placement of the exchanger is well below the top of the boiler, a small hydrostatic head at this point will not make any particular difference.

It will be at once apparent that no heat can pass from the boiler I to the heat exchanger 4 unless the power driven pump 8 is operated and that when the pump 8 is stopped by control means stopping its motive power, the transference of heat from the boiler to the exchanger stops abruptly. Further, owing to the small volume of hot water contained in the exchanger, the effect of thermostatic control is immediate and therefore more accurately reflected in room temperature.

In the drawings, to complete the disclosure, a fan I is operated by a motor H, which in turn is controlled by a remotely located thermostatic control, diagrammatically indicated by the connections l2. In the modified device as shown in Fig. III the pump 8 will be the same but will be provided with an individual motor 35, which in this case is the motor remotely controlled by room temperature as indicated by the broken circuit 30 and the fan l0, operated by the motor II, which will have in this case connections i3! adapting it for constant operation.

The modified result is seen by considering the small changes in the set-up of instruments. The motor H in each case delivers air to the duct 40 which will convey it to the point or points where it is wanted. The air passes through the exchanger 4 where heat is added, in both cases, but where constant circulation is desirable because of a considerable number of people in the heated zone, the temperature is maintained by starting and stopping the pump, which, due to the thermosyphon influence being successfully circumvented by fiat placement of the exchanger and taking both water pipes off the top, or near the top of the boiler at the same level, prevent any other mode of operation. 7 7

Where a hot water boiler is furnished with out let and inlet pipes near the top as described, an accumulation of entrained air and noncondensable gases that can find their way into the pipes will be trapped there and seriously interfere with their proper functioning. To guard against this happening, I locate an upwardly extending vent pipe at the highest point of the boiler top, bring it over in a hairpin bend and submerge the free open end in a small container within which has been placed sufiicient water to hermetically seal the open end of the pipe.

This pipe serves two purposes, to prevent heat expansion from producing a very high pressure that would damage the exchanger, and to get rid of the air as stated.

This arrangement is a valuable part of the combination when the pipes are arranged as shown. It is illustrated in the drawing as the dotted arcuate line 15, which diagrammatically illustrates a high point in the boiler top, the hairpin bentpipe ll and the water sealing container'IB.

This arrangement does away with the extra load of pumping through a loaded control valve and the uncertainty of an electrically operated flow control, at the same time permitting the exchanger to operate with a very moderate hydraulic head pressure.

When the pump 8 stops, in either case, there will be a practically instantaneous stoppage of heat flow from the boiler to the exchanger and the system has a far less two-way variation of temperature than before.

The important thing is to do away with thermosyphon circulation without the use of cut-off valves, whereby we get a closer regulation of heat delivered from the boiler, which will always supply whatever is demanded up to its final capacity.

Having disclosed my invention, explained its principle and shown an exemplification of the way it can be applied, what I claim as new and desire to secure by Letters Patent is--- 1. In a hot water heating system, a boiler, a

flat horizontally placed heat exchanger adjacent to and. below the top of the boiler, supply and return pipes between the boiler and the exchanger both of which are connected near the top of the boiler at similar levels to avoid thermosyphon circulation, and a controlled pump in one of the pipes.

2. In a heat transfer apparatus comprising a boiler and a heat exchanger substantially below the top of the boiler, a pair of pipes one being a heated water supply means from the boiler to the exchanger and the other being a return pipe, a circulation pump interposed in one of the pipes and a remotely located control for the pump, and air circulation means through the exchanger to the space where the control is located, characterized by the two pipes being connected to the boiler near the top thereof and at the same level and the pipes being connected to the exchanger in such manner that the hydrostatic head within the exchanger is substantially less than the distance from the top of the exchanger to the level of the pipe connections to the boiler.

3. In a heat transfer apparatus, a boiler, a heat exchanger adjacent to and below the top of the boiler, inlet and return pipes between the boiler and the exchanger, a circulation pump in one of said pipes, air circulation means arranged to pass air through the exchanger to the space to be heated, and control for the pump in said space, characterized by both the inlet and return pipes being connected to the boiler at the same level near its top, opposite ends of said pipes being connected to the exchanger at nearly a common level, whereby hydrostatic head therein is insuificient to induce thermal movement of its contents.

4. In a heating system, a hot water supply means, a heat exchanger located adjacent to but spaced below the level of water supply from said means, inlet and return pipes connecting the exchanger to said hot water supply means both being connected to said means at the same level but spaced apart, opposite ends of said pipes being connected to the exchanger at opposite sides thereof and in nearly the same horizontal plane, a circulation pump in one of said pipes, a control for the pump and means for circulating air through the exchanger to space to be heated.

ELMER E. GOEHLER. 

